POD GO - Using MIDI to change patches on MIDI Amplifier

[adrian_52]

Hello everyone!

On my journey to control my Blackstar One 100w 6L6 channels and use 4 cable method, I was reading the Line 6 Pod Go manual where it's stated that every hardware preset change pushes a PG MIDI message towards the USB connected device (normally a computer).
 

Quote

NOTE: When navigating Presets from the POD Go hardware, POD Go automatically
transmits a MIDI Program Change message corresponding to the selected preset.
If you’d prefer to not automatically transmit PC messages, set “Global Settings >
MIDI/Tempo” > Tx/Rx MIDI PC to “Off.”

Now, my idea was to use a MIDI USB HOST device which transmits these Program Change messages towards a MIDI Cable and then towards the amplifier so the Amplifier changes the channel according to the Program Change message received, as an example my AMP:

1 CLEAN
2 CRUNCH
3 OD1
4 OD2
...
5 CLEAN
6 CRUNCH
7 OD 1
8 OD2
...
and so on until 128...

However, I've found out that when plugging the Pod Go via USB to the MIDI USB HOST device, the POD GO isn't sending any PG message and obviously the AMP is not receiving anything.

I've read somewhere around internet that this might be because the Pod GO is also an audio interface, so those messages are not retransmitted JUST with the USB compliant (without drivers).

I would like to know if this is a bug or if this is expected behaviour. I know Helix have MIDI outputs, but I am happy with this product and I have more than enough effects and what-not from it and would be a pity to be forced to carry something bigger, heavier and way more expensive just for the fact of having dedicated MIDI and being able to change channels on my amp integrated with MIDI.

Thanks for reading!

Adrian

[adrian_52]

Hello folks,

As I see there's not much of an answer I decided to investigate myself on this and indeed I've found some interesting information:

1. I loaded a linux distro (Ubuntu) into my PC and I could see the Line 6 Pod GO MIDI interface there without any particular drivers installed.
2. I dumped the midi messages from the Pod GO USB midi interface and indeed I could see the program change messages sent from the Pod GO to the computer everytime I press a preset button on the Pod GO. This is good.

What I will try to do now is buy a Raspberry PI with a USB -> MIDI cable, then try to route somehow the MIDI messages sent from the Pod GO into the USB-MIDI cable MIDI OUT towards MIDI IN in the amplifier. This way I can use the AMP clean/distortion channels and the Pod GO will be the one sending the MIDI Program Change messages towards the AMP, so I have no need to use any AMP simulation anymore, just the effects I desire to have before preamp of after preamp (4 cable method), and I eliminate the need of using the amplifier channel pedalboard.

The good news is that Blackstar took the MIDI thing in a serious way and there is away to 'teach' the amp which Program Change number changes which channel.

The price for this is that I will need to have a Raspberry Pi next to my amplifier and pod go, but I thought a good velcro might work wonders so it is always attached at the amp in the back so it's not seen. I also thought that once everything is configured and tested, I can turn the Raspberry Pi OS into read-only system - this way no matter how many times I pull the power cable out of the raspberry PI the system won't get corrupted.

If I have success with this, I will share the tutorial of how I did it - I believe it should be simple.


Adrian

[cruisinon2]

On 8/21/2024 at 11:59 AM, adrian_52 said:

If I have success with this, I will share the tutorial of how I did it - I believe it should be simple.

 

 

One man's "simple" rig is another's Rube Goldberg contraption...;) Just contemplating that much signal gymnastics and add-on hardware, especially in a live situation, gives me a migraine. Best of luck in your quest, though! :)

[adrian_52]

Hello Cruisinon2,

In theory, after it's configured it should be fairly simple and you can just plug the AC off or on without worrying about breaking anything:

1. Pod GO standard 4 cable method
2. Pod go USB -> Raspberry PI -> USB to MIDI cable into AMP's MIDI IN.

That's it - the Raspberry PI you can velcro it to the back of the AMP with the MIDI OUT connected to MIDI IN of AMP. So in a live situation you just have to worry about the POD GO USB connected to the raspberry pi, this allows you to save one cable from one big device... the pedalboard of the AMP :)

I get your point, hacks are hacks... but... do you want to swap amp channels with your Pod GO? That's the price!

Adrian

[adrian_52]

Hello Everyone,

I've managed to execute my plan (heh). When using a stock raspberry PI OS (everything that you need comes installed, like ALSA), it receives the midi Program Change commands sent by Pod GO USB, so you can just plug a USB to MIDI device (cheaply found anywhere) and redirect the MIDI PG messages from the POD GO to it via "aconnect" command on console. 'aconnect' can route MIDI messages from one device to another.

What I also did is put this command in /etc/rc.local so the 'aconnect' command is ran everytime the raspberry boots.

The next step I did was to put the whole system Read Only, this way the SD card won't get corrupted by turning on or off the device by pulling the power plug off.

How it looks? In the back of the AMP I've velcro the raspberry so:

POD Go USB -> Raspberry PI (long USB cable 5 or 6 meters, I've bought a 10 meter USB cable to see if it works).
Raspberry PI USB -> USB to Midi device -> Midi Out to the MIDI IN of the amp.

So the only thing you really see is the USB cable from the Pod GO to the back of the AMP - the rest is behind the AMP.

I'll test it today and I'll show you the pictures of how it looks like behind the amp and a working video.


Regards,
Adrian